Can someone recommend a reasonably price one ,that you can use from 17 cal. and up and works in AR's also . Thank you

I have an old Bushnell, gets me on paper at a hundred, but won’t work on my two AR’s. I sighted one in today at 25 yds, then moved back to a hundred.

I have a cheap BSA bore sighter. It works well enough to get on paper at 100 yds.

https://www.sportsmansguide.com/product/index/bsa-boresighter-kit?a=1174794

I've had two: a Bushnell years ago and a Leupold for the last few years. Both have given about a 50/50 chance of getting on paper at 100 yards. Much better at twenty-five. With a bolt-action rifle, bore sighting works about as well. There are probably better units out there than what I've used.

I have the BSA set as well. Always gets me on paper at 50 yards, might work at 100 but I start at 50..

One thing I've pointed out before in a few places is that ANY bore-sighter (collimator) needs to be "sighted-in." You do this by mounting it on an already sighted-in rifle (or preferably, several) and see where the scope's reticle is on the collimator screen.

It will NOT be in the same place for all rifles, due to a couple of factors, but will usually be in a general area somewhere AROUND the center of the screen. The middle of that area is where you need to move the scope reticle to have a good chance of bullets landing close to center on a target at 100 yards.

Some collimators can even be adjusted so the reticle of a sighted-in rifle is centered in the collimator screen, but tend to be more expensive, so may not meet Longbow's definition of "reasonably priced."

Collimators that attach with a magnet, rather than metal "spuds" inserted in the to muzzle, are more versatile and usually less expensive, but also tend to be less accurate, because they depend on the squareness of the muzzle, rather than bore itself. But they can used on just about any rifle--or even shotgun slug barrels.

Mine's a BSA I actually got by winning Penguin's You Pick 'Em football pool one year. It works. All these are to do is get you on the paper. In no way is your gun ready to go hunting after bore sighting. The arbor set that came with the gun covers everything from .17 up to .50 caliber. When I worked at the rifle range many years ago, they ran 4 of the Bushnell boresighters. I never saw it done, but I know they calibrated them before putting them into use, and it did make a difference. We never had a gun not be centered on the paper at 50 yards after the first shot, assuming the shooter had decent shooting skills. My BSA seems to be about an inch low and to the right at 50 yards, so I compensate for it slightly when I set the crosshairs before shooting.

Never got into the collimator idea, mostly because a visual thru the bore in comparison to the crosshairs/peeps on target does the trick most days. Some guns don't let one do that of course, but that's why the 25 yard line was invented maybe?

I inherited one from my father. I tried it a few times. It wasn't any more effective than a 25yd dot on cardboard, then a target at 100 as far as actual shots fired to get on paper. Maybe I should what Mule Deer suggests, but I find it just as easy to shoot at a close target once, adjust scope, and go to 100.

These threads always question the value of a collimator--though they're almost always called "bore-sighters."

I have also pointed out before that their best use is not in getting sighted-in, but in making sure a scope is properly aligned with the bore during mounting. This prevents all sorts of problems, including erratic adjustments.

I've never felt that one could saved me a single round, nor a minute of my time getting a rifle zeroed. With a bolt rifle I simply bore sight at 50 yards and then fire one shot at 50. I'm usually within 2" then I fine tune and shoot shot #2 at 100 and fine tune again. Shot #3 is zeroed. I've never found a bore sight tool that could get the 1st shot any closer.

With a rifle that I can't bore sight easily I just make sure I use a target big enough to ensure that I hit paper with shot #1. It doesn't really matter if the 1st shot is 10" or 1" from zero. As long as you have a hole in the paper it is simply a matter of adjusting the scope the correct amount.

+1 . Mine has gotten me on the paper at 100 yards 100% over 15 years.

It has the added benefit that if you take a measurement of the deflection after you've got it zeroed, you can use that for comparison later. This answers the question: did I knock the scope off kilter in transport?

A pc of old brass with the primer knocked out then inserted in the chamber works well on bolt guns.
I like using those orange or green target dots so it's easier to see them.

I have this one also, and it has always worked for 25 yards, which is where I always start anyway. I have had it work at a 100, but since I don't start that that distance, I don't know how reliable it would be.

I don't ever use one. If it's a rifle I can't look through the bore on, like an M1 or a lever, I just shoot at 25yds & adjust.
With bolt actions I remove the bolt and sight down the bore. ARs, just remove the upper from the lower and remove the BCG and do the same thing. With a steady rest, it works very well. Just remember to add elevation.

What's wrong with the laser type that sticks in the end of the barrel? I've had a Cabela's branded one for years. It has different plastic bushings so it fits snug in different bores. I usually stick it in, adjust scope, pull it out and reinsert it, adjust again if needed. Seems to work fine on every gun I've used it on.

Nothing. There's always more than one way to skin a cat.

I use a Bushnell magnetic boresighter, after mounting a scope. Boresighters put you in the ballpark (on paper). Follow the instructions and you should find bullet holes at 25 yd. I have a wooden straight edge that I hold against the scope to rough align the boresighter to my scope. How many times have you watched someone struggle with his rifle at the range, trying to find a solitary bullet hole? Take pity on them and help, if you can. I use this particular one because it is small, portable and can be used with any action type.



I used to harmonize F104 and F5 aircraft 20mm guns. The 104 was done at a 25 yd butt. Harmonizing is actually matching the gun sight with the gun because the HUD isn't attached directly to the gun itself. The a/c was jacked and 25 rds was fired into a backstop. Whenever we had a new technician on the crew, he would get to sit in the cockpit and squeeze the trigger. We always told him, "Don't forget to lift your feet before you squeeze the trigger!" There was no need to do this, but that started years ago as a joke and people just kept saying it.

F5s were done differently, using a 1000 inch white board and bore sighter. As you can imagine, it was quicker, easier to fix SA sights.

Here's an older pic of some RCAF armourers harmonizing the 50 cal guns on an F86. Look closely and you can see the a/c was jacked to disable the weight on wheels switch. I can't find any CF5 or CF104 harm photos.

Interesting this topic came up. I have a Bushnell that I’ve been using for years. The spuds are about done. Can you buy replacements .
Or is it time for a new one. Hasbeen

So a solid rest is important, even with aircraft.

It all comes down to individual preference really. However, I will say that after several decades of trying to mount scopes without my BSA bore sighter, I found that it simplified the process.

25 yard shots will get you your windage adjustment up to a point, but it will not get you elevation.

The BSA bore sighter I have has payed for itself many, many times over in saved ammunition, and it's answered a lot of questions along the way.

I have several and keep turning to the Bushnell; Leupold has one that just doesn't work as well.

MD,

Can you recall which collimators can be adjusted so the reticle of a sighted-in rifle is centered on the collimator screen?

Thanks.

Can the spud style collimator damage the barrel?

I suppose it could if one was careless. The spud is undersized with a little spring loaded wire that holds the spud in, at least that is what the BSA models use. No adjustments for the collimator.

The spring loaded wire is brass on my set. It shouldn’t hurt anything.

I've never seen any damage in a bore-scope.

The Bushnell I've had for 40 years now can be adjusted. Dunno about the latest models.

Does Bushnell still make the model with the spuds and if so where to purchase such item?

I'd try Brownells or contact Bushnell directly.

Yes, they do, and price is under $100 with 4 expandable spuds (or arbors, as they call them). You can also order a kit with a bunch of bore-specific, non-expandable spuds

There are also some very good laser bore-sighters. I also have a magnetic laer from MidwayUSA that fits on the muzzle and works very well, but many are cartridge-specific models that, for instance, fit in a .30-06 chamber. They also work well, but are of course limited to rifles chambered for that round.

I look down the bore at a target, ang get on paper every time.

The OP specifically asked about AR's. While it's entirely possible to look down the bore in an AR, it involves some disassembly.

A bunch of other actions also don't allow looking down the bore while tweaking the scope.

I guess you got me there.

The key to looking down the bore is to have the upper (or the rifle) on bags or a rest or even just on a flat, solid surface in the case of an AR upper separated from the lower. It can't move between looking down the bore & twisting the knobs.

That isn't critical with lasers & collimators.

I am amazed that turret twisters aren't all about them. No better way I know of to make sure you're scope is optically centered after sighting in.

A lot of people talk about making sure the scope is centered before mounting. If you aren't using some kind of adjustable ring or mount system, it doesn't really make a hoot that I can see. Adjustments are going to end up where they need to be to get sighted in. Having the scope centered before hand may or may not make it a little easier to get on paper if you don't do some kind of bore sighting. If everything is perfect with the set-up it may help but not necessarily. I have saw two very accurate loads hit about 4 inches apart left/right of each other.

To me, a bore sighters most important use if after getting sighted in. As somebody else already stated, you can make a note of where the crosshairs end up to know at a quick glance if something has happened since you sighted in. Even more important is getting the scope centered after sighting in.

Basically, get sighted in. Take a reading of where the crosshairs are in the grid. Then optically center your scope and use your ring or base system to bring the cross hair to within a click or two of where it was on the grid after you got the initial sight in. Now your scope is mounted, very near the optical center and sighted in. It will give you the most travel up and down inside the tube if it is centered. If you later change loads and the new load is hitting significantly left or right of the original load, you may want to go through the process again, especially if you're a twister.


ymmv.

If one is into long range shooting and will twist turrets for bullet drop at long range, why would you want to optically center your reticle after zeroing in? A canted base to allow more adjustment vertically is what most do, such as a 20 MOA angled base.

I think he's talking mostly about wind.

I always thought this was self evident, but realize that the line of sight and bullet trajectory path both occur way below the bore line. A strictly bore sighted rifle is not sighted in at all, but will be usually shooting higher than needed at downrange targets. That at least has been my experience. The trajectory line crosses the line of sight twice (both times below the bore line), once in the neighborhood of 25 yards (hence usually being on paper there), again at whatever range the shooter sights in the rifle. Changing ring height will change things as well.

Unfortunately, my experience has taught me that a bore sighted rifle can shoot high, low, left or right or a combination of the preceding

As I noted in a earlier post on this thread, for the best use a collimator should be "sighted-in" by sticking it on the muzzle of several sighted-in rifles, and noting where the center of the reticle ends up on the collimator screen. That point will vary some from rifle to rifle, due to barrel contour, cartridge, etc., but you can generally come up with an average point which will be pretty close for most rifles.

Agreeed.

I put this together quickly, but I hope that the idea comes through.

Some shooters have difficulty finding a bullet hole at 25 yd because the reticle is not aligned with the target. They put on a scope at home and head off to the range. When they aim at the bull and fire, the bullet hole is nowhere to be found. Where did it go? Worse, the amount of error increases the farther the rifle is from the target. That is why most sighting in is done at close range.

What you want to do first, even before you mount the scope on the rifle, is ensure that the lenses are close to being centred in the scope as possible. This is for hunting scopes, and will give you the maximum adjustment in all directions. It is good to do with scopes that have been moved from one rifle to another, or that you got used.

You begin by locating the mechanical centre of the scope. Start by cranking your elevation all the way to the top. Next, you are going to crank it all the way to the bottom, counting the number of clicks it takes to get there. Then crank it into the middle. Ex. if the number of clicks from top to bottom is 100, crank it up 50 (halfway). Repeat this for the windage. Mount the scope, or if it is already on your rifle, it's time to attach the boresighter.

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In a perfect world, the centre of your scope and boresighter would be in alignment. The reality is, they rarely are. If they were properly aligned, the small cross hairs indicating the centre would look like one in the pic below.

You want to get the boresighter lined up as close as you can to the scope. For this explanation, let's assume that the scope is perfectly parallel with, and properly aligned to the centre of the bore. Attach the collimator, which most people here call the boresighter. You want to get the two as close as you can to being perfectly aligned.

I use a magnetic boresighter, and gently attach it to the muzzle.. Then I hold a yardstick to the centreline (longitudinal axis) of the scope and centre my collimator to the line of the yardstick. Next, I look down on my rifle from the top, and align the yardstick so that it is centred along the longitudinal axis of the scope. I use the straight edge centre the collimator.

I look through the scope and make the adjustments to zero the scope's cross hairs with the collimator grid.

This always gets me on paper.
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Using a straight edge and a magnetic boresighter is a rough adjustment. The scope is not zeroed. When you read advertisements saying that the store is selling scoped rifles that have been boresighted, it really doesn't mean anything. Assuming that they performed the boresighting properly, you still have to zero the scope with your loads. And I would still check with my boresighter.

Steve,

Which is exactly why magnetic collimators are usually better at elevation settings--if used correctly--and why spud-type collimators often show a few inches difference in elevation, even when used correctly:They can't be adjusted for scope height.

Probably most accurate collimator I own is a magnetic laser model, one of the Midway brands. But like any laser collimator, it requires considerable space in front of the barrel to provide good alignment--not as much as actual boresighting, but pretty close.

That's true, John. I didn't want to get into the differences between them. From what I have seen over the years, even people who own a collimator do not use it properly.

They are like a new tool the more you use them, the better you get, I have a sitelite that I am getting pretty handy with I am on paper at 100yds everytime !!!!

Think windage, not elevation.